ANTENNA SWITCHING AND UPLINK SOUNDING CHANNEL MEASUREMENT
First Claim
1. A method that facilitates downlink precoding in antenna configurations with unequal number of transmit and receive chains, comprising:
- transmitting a modulated sounding reference signal on each antenna in a plurality of antennas, the modulated sounding reference signal compensates for discrepancies in device transfer functions between downlink and uplink;
transmitting a non-modulated sounding reference signal on each antenna in the plurality of antennas; and
alternately connecting a transmit chain to each antenna in the plurality of antennas to facilitate transmission of sounding reference signals on the plurality of antennas.
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Accused Products
Abstract
Systems and methodologies are described that facilitate employing downlink precoding based on uplink sounding channel measurement and channel reciprocity in time division duplex or time division multiplex systems. In particular, mechanism are provided that enable downlink precoding in situations where user equipment antenna configuration includes an unequal number of transmit chains and receive chains. A mobile device transmits modulated sounding reference signals on each antenna during a calibration stage. The mobile device then transmits non-modulated sounding reference signals during a normal mode. A base station utilizes the modulated and non-modulated sounding reference signals to restore a downlink channel estimate employed in downlink precoding.
138 Citations
40 Claims
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1. A method that facilitates downlink precoding in antenna configurations with unequal number of transmit and receive chains, comprising:
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transmitting a modulated sounding reference signal on each antenna in a plurality of antennas, the modulated sounding reference signal compensates for discrepancies in device transfer functions between downlink and uplink; transmitting a non-modulated sounding reference signal on each antenna in the plurality of antennas; and alternately connecting a transmit chain to each antenna in the plurality of antennas to facilitate transmission of sounding reference signals on the plurality of antennas. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A wireless communications apparatus, comprising:
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a memory that retains instructions related to transmitting a modulated sounding reference signal on each antenna in a plurality of antennas, the modulated sounding reference signal compensates for discrepancies in device transfer functions between downlink and uplink, transmitting a non-modulated sounding reference signal on each antenna in the plurality of antennas and alternately connecting a transmit chain to each antenna in the plurality of antennas to facilitate transmission of sounding reference signals on the plurality of antennas; and a processor, coupled to the memory, configured to execute the instructions retained in the memory. - View Dependent Claims (8, 9, 10)
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11. A wireless communications apparatus that facilitates downlink precoding in antenna configurations with unequal number of transmit and receive chains, comprising:
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means for transmitting a modulated sounding reference signal on each antenna in a plurality of antennas, the modulated sounding reference signal compensates for discrepancies in device transfer functions between downlink and uplink; means for transmitting a non-modulated sounding reference signal on each antenna in the plurality of antennas; and means for alternately connecting a transmit chain to each antenna in the plurality of antennas to facilitate transmission of sounding reference signals on the plurality of antennas. - View Dependent Claims (12, 13, 14, 15, 16)
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17. A computer program product, comprising:
a computer-readable medium comprising; code for causing at least one computer to transmit a modulated sounding reference signal on each antenna in a plurality of antennas, the modulated sounding reference signal compensates for discrepancies in device transfer functions between downlink and uplink; code for causing at least one computer to transmit a non-modulated sounding reference signal on each antenna in the plurality of antennas; and code for causing at least one computer to alternately connect a transmit chain to each antenna in the plurality of antennas to facilitate transmission of sounding reference signals on the plurality of antennas. - View Dependent Claims (18, 19)
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20. In a wireless communications system, an apparatus comprising:
a processor configured to; transmit a modulated sounding reference signal on each antenna in a plurality of antennas, the modulated sounding reference signal compensates for discrepancies in device transfer functions between downlink and uplink; transmit a non-modulated sounding reference signal on each antenna in the plurality of antennas; and alternately connect a transmit chain to each antenna in the plurality of antennas to facilitate transmission of sounding reference signals on the plurality of antennas.
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21. A method that facilitates downlink precoding based on sounding channel measurement in user equipment antenna configuration with unequal number of transmit and receive chains, comprising:
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receiving modulated sounding reference signals, the received modulated sounding reference signals are received from each antenna among a plurality of antennas of a mobile device; receiving non-modulated sounding reference signals from each antenna among the plurality of antennas of the mobile device; restoring downlink channel information utilizing the modulated sounding reference signals and the non-modulate sounding reference signals; and performing downlink precoding based at least in part on the restored downlink channel information. - View Dependent Claims (22, 23, 24, 25, 26)
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27. A wireless communications apparatus, comprising:
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a memory that retains instructions related to receiving modulated sounding reference signals, the received modulated sounding reference signals are received from each antenna among a plurality of antennas of a mobile device, receiving non-modulated sounding reference signals from each antenna among the plurality of antennas of the mobile device, restoring downlink channel information utilizing the modulated sounding reference signals and the non-modulate sounding reference signals and performing downlink precoding based at least in part on the restored downlink channel information; and a processor, coupled to the memory, configured to execute the instructions retained in the memory. - View Dependent Claims (28, 29, 30)
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31. A wireless communications apparatus that facilitates downlink precoding based on sounding channel measurement in user equipment antenna configuration with unequal number of transmit and receive chains, comprising:
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means for receiving modulated sounding reference signals, the received modulated sounding reference signals are received from each antenna among a plurality of antennas of a mobile device; means for receiving non-modulated sounding reference signals from each antenna among the plurality of antennas of the mobile device; means for restoring downlink channel information utilizing the modulated sounding reference signals and the non-modulate sounding reference signals; and means for performing downlink precoding based at least in part on the restored downlink channel information. - View Dependent Claims (33, 34, 35, 36)
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32. The wireless communications apparatus of claim 32, further comprising means for generating calibration factors based upon the received modulate sounding reference signals, the calibration factors compensate for discrepancies between downlink and uplink device transfer functions.
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37. A computer program product, comprising:
a computer-readable medium comprising; code for causing at least one computer to receive modulated sounding reference signals, the received modulated sounding reference signals are received from each antenna among a plurality of antennas of a mobile device; code for causing at least one computer to receive non-modulated sounding reference signals from each antenna among the plurality of antennas of the mobile device; code for causing at least one computer to restore downlink channel information utilizing the modulated sounding reference signals and the non-modulate sounding reference signals; and code for causing at least one computer to perform downlink precoding based at least in part on the restored downlink channel information. - View Dependent Claims (38, 39)
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40. In a wireless communications system, an apparatus comprising:
a processor configured to; receive modulated sounding reference signals, the received modulated sounding reference signals are received from each antenna among a plurality of antennas of a mobile device; receive non-modulated sounding reference signals from each antenna among the plurality of antennas of the mobile device; restore downlink channel information utilizing the modulated sounding reference signals and the non-modulate sounding reference signals; and perform downlink precoding based at least in part on the restored downlink channel information.
Specification